Pelagomanes kozoi ( Renaudie and Lazarus, 2013a ) Trubovitz, Sarah, Renaudie, Johan, Lazarus, David & Noble, Paula, 2022

Trubovitz, Sarah, Renaudie, Johan, Lazarus, David & Noble, Paula, 2022, Late Neogene Lophophaenidae (Nassellaria, Radiolaria) from the eastern equatorial Pacific, Zootaxa 5160 (1), pp. 1-158 : 81-82

Pelagomanes kozoi ( Renaudie and Lazarus, 2013a) n. comb.

Plate 39, Figs. 1–6 .

Lithomelissa setosa Jørgensen, Takahashi, 1987 , pl. 5, fig. E.

? Ceratocyrtis ? sp. aff. C. stigi (Bjørklund) , Sugiyama and Furutani, 1992, pl. 13, fig. 13.

Lithomelissa sp. D , Itaki et al., 2008a, pl. 1, fig. 6.

Lithomelissa sp. D , Itaki et al., 2009, pl. 17, figs. 15–23.

Lithomelissa? kozoi n. sp., Renaudie and Lazarus, 2013a, pl. 5, figs. 10a–11, 13a–b; pl. 8, fig. 5.

Lithomelissa? kozoi Renaudie and Lazarus, Trubovitz et al., 2020 , supplementary data 7.

Remarks. In our plates we provide images of Pelagomanes kozoi from both the EEP and the SO, where it was originally described. Figures 1–4B are of specimens observed during this study in the EEP. Specimen 6 is the holotype and specimen 5 is another specimen that was figured by Renaudie and Lazarus 2013a in their description. Both specimens are from the Late Pliocene Southern Ocean. Among the SO and EEP specimens there are some variations in overall size and shoulder development. This species differs from Pelagomanes ibburi n. sp. (Pl. 41, Figs. 1A – 6B ) in that it has multiple teeth of approximately equal strength, rather than three feet stronger than the rest. It differs from P. stigi (Bjørklund) (Pl. 39, Figs. 7–9 ) in having relatively smaller pores throughout the cephalis and thorax, more distinct shoulders and ribs, and usually a less prominent apical horn. P. kozoi is smaller than P. thaumasia (Pl. 39, Figs. 10A –11), has more shoulder development, is usually not as heavily silicified, and has more prominent teeth at the base of the thorax. This species differs from P. cantharoides (Pl. 40, Figs. 1–3 , 7–8 , 10 , 14 ) in that the apical horn is not as strong, and it does not have any additional branching on the dorsal side. P. kozoi is smaller than both P. cantharoides and P. morawanensis (Pl. 40, Figs. 4A – 6 , 9 , 11–12). Based on our understanding of P. tekopua ( O’Connor 1997) (pl. 40, Fig. 13 ), P. kozoi differs in having a relatively smaller cephalis:thorax ratio and lacks bladed apical and ventral horns.

Range. Lower Late Miocene—Latest Miocene, EEP ( Table 1 ). Observed from the Late Miocene– Early Pleistocene in the Southern Ocean by Renaudie and Lazarus (2013a).

Figures

FIGURE 1. Diagram illustrating the general skeletal morphology of Lophophaenidae, and terminology used in this manuscript. Dashed lines indicate spines that are not visible from the angle shown, as they extend into the skeleton. An example specimen of Lophophaena casperi n. sp. is included for comparison to the diagrams.

FIGURE 2. Relative abundance of specimens and taxa belonging to Plagiacanthoidea and Lophophaenidae per sample, from IODP Site U1337 in the EEP over the last ~10 Ma. The relative percentages of total taxa are represented by the blue lines and the red lines represent the percentages of total specimens (triangles = Plagiacanthoidea; circles = Lophophaenidae). The Plagiacanthoidea was among the most abundant and speciose of radiolarian groups encountered in Trubovitz et al. (2020), with at least 10% of the specimens and 20% of the taxonomic richness in every sample. Within the Plagiacanthoidea, lophophaenids consistently made up the majority of specimens (~67%) and taxa (~61%). Data are from Trubovitz et al. (2020).

FIGURE 3. Locality map of IODP Site U1337, where all samples for this study were collected. Map from Google EarthTM.

FIGURE 4. Examples of specimen measurements discussed in the Systematic Paleontology section of this study.

FIGURE 5. Internal skeletal structure of Amphiplecta acrostoma Haeckel, 1887.

FIGURE 6. Internal skeletal structure of Arachnocorallium calvata (Haeckel, 1887) Petrushevskaya, 1971.

FIGURE 7. Internal skeletal structure of Arachnocorys umbellifera (Haeckel, 1862) Petrushevskaya, 1971.

FIGURE 8. Internal skeletal structure of Botryopera amabie n. sp.

FIGURE 9. Internal skeletal structure of Ceratocyrtis sp. C.

FIGURE 10. Internal skeletal structure of Lithomelissa alkonost n. sp.

FIGURE 13. Chart illustrating the differences between Lophophaena gozui n. sp. (orange diamonds) and L. ushionii n. sp. (green squares), in terms of cephalis height and the ratio between thorax and cephalis width. L. gozui has a shorter average cephalis height (40 microns) compared to L. ushionii (average cephalis height = 54 microns). In addition, the thorax is proportionally wider compared to the cephalis in L. gozui (average ratio of thorax:cephalis width = 2.5). L. ushionii has a proportionally narrower thorax (average ratio of thorax: cephalis width = 1.5).

FIGURE 14. Chart illustrating the different cephalis sizes in Lophophaena shishigae n. sp. and Arachnocorys jorogumoae n. sp. The yellow circles indicate L. shishigae, with a small cephalis, and the purple triangles represent A. jorogumoae, with a significantly larger and proportionally higher cephalis.